Railway traffic controlling apparatus



June 1, 1937, E. M. ALLEN RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed April 23. 1931 2 Sheets-Sheet l INVENTOR.

E-MJ HIen, 6272f M ATTORNEY.

June 1, 1937. E. M. ALLEN RAILWAY TRAFFIC CONTROLLING APPARATUS ZSheets-Sheet 2 Original Filed April 23, 1931 INVENTOR. E. M, A! Ian 7 11M A a ATTORNEY.

8 L FL ./.%v E mm N 3 2 L Q S b B Q v Q Q QU N m a F m3 aw NM Patented June 1, 1937 UNITED STATES insane PATENT @EHQE RAILWAY TRAFFIC CONTROLLING APPARATUS Application April 23, 1931, Serial No. 532,174

Renewed September 15, 1932 19 Claims.

My invention relates to railway'trafiic controlling apparatus, and particularly to apparatus of the type comp-rising traiiic governing devices for both directions of trafilc selectively controlled by manually operable means to permit traffic movements in one direction or the other.

One feature of my invention is the provision of means for permitting traffic movements in a given direction only if an app-roach locking relay for that direction is deenergized while an approach locking relay for the opposite direction is energized.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

Theaccompanying drawings, Figs. 1a and lb, when placed end to end, with Fig. 1a on the left, constitute a diagrammatic view showing one form of apparatus embodying my invention.

Referring to the drawings, a stretch of railway track AI is shown equipped with signals designated S S S S S S S 8*" and S, respectively, for governing trafiic normally moving westward,.that is, from right to left as 5 shown in the drawings. Eastbound traffic movements may also at times be permitted over stretch A-I by signals. designated by the reference' characters S S S S S S S S and S respectively. Signals S S and 30 S operate contacts 5, 6 and 1, respectively, each of which is closed when and only when its signal is indicating stop. Signals S S and 8 operate corresponding contacts 5, 6, and 1, respectively, each of which is closed when and 35 only when its signal is indicating stop.

Rails I and I a of stretch A-I are divided by insulated joints 2 to form a plurality of sections designated A- B, B-C, CD, D E, E.F, FG, GH and HI, respectively. Each of 40 these sections is provided with a track circuit including a battery 3 connected across the rails adjacent one end of the section and a relay designated by the reference character T with a distinguishing exponent and connected across the rails adjacent the opposite end of the section.

Track switches designated by the reference characters J J and J are located-in sections BC, D-E and GH, respectively. As here shown, switch J is arranged to be operated between normal and reverse positions by a motor designated by the reference character M. Switch J may be operated by any suitable manually operated mechanism, not shown in the drawings. A lock bar I) is rigidly secured to the 55 switch J for engagement by a dog a, by means of which the switchmay be locked in its normal position in which it is shown in the drawings. Dog a is actuated by a manually operable lever X which has normal and reverse positions designated by the reference characters m and 1', respectively. Movement of lever X is controlled electrically by means of a lock magnet at having an armature provided with a dog 60 for engagement with a notch 6| of a locking segment a. Segment 9 is rigidly connected to lever X. Switch J may be operated by, any suitable means, not shownin the drawings.

Eastbound traffic movements into portion B-H of stretch. A-I are controlled by signals S Westbound traffic movements into portion BH of stretch .A--I are controlled by signals S A lever designated by the reference character V and having a normal position n, a reverse position to the left is, and a reverse position to the right 1*, is provided for controlling signals S Lever V operates a contact i which is closed while lever V occupies its n position or any position to the left of its 11 position, but which is open when lever V is moved toward the right from its n position. Lever V also opcrates a contact2l which is closed when and only when lever V occupies its 1' position.

An approach locking relay associated with signals S and designated by the reference character P is controlled in part by contact 4 of lever V and in part by contacts 5, ii, and 'l of signals S The control of relay P by these contacts is such that this relay will become deenergized whenever any one of these contacts is opened.

A slow pick-up relay designated by the reference character L is also controlled by the same lever contact 4 by contacts 5, 6, and l of signals S and by a back contact of relay P A stick relay K has a pick-up circuit controlled by front contacts' l2 and it of relays P and T respectively, and has a stick circuit controlled by a front contact of relay P A lever V similar to lever V is provided for controlling signals S Lever V however, operates a contact 4 which is closed while lever V occupies its n positionor any position to the right of its 11. position, but which is opened when lever V is moved towards the left from its n position. Lever V also operates a contact 42 which is closed when-and'only when lever V occupies its 70 position.

An approach locking relay P is controlled similarly to approach locking relay P already described, so that when any one of the contacts, l of levers V and 5, 6 and I of signals S is open, relay P will be deenergized. A slow pickup relay L is controlled similarly to relay L as already described, and a stick relay K is controlled similarly to stick relay K Relays K and K control a circuit which includes three polarized relays connected in series each of which is designated by the reference character Q with a distinguishing exponent. Relays Q are so designed that their polar contacts, after becoming closed when the corresponding relay is energized in a given direction, will remain closed in the corresponding position until the relay is energized in the opposite direction. When relay K is energized and relay K is deenergized, relays Q are energized by current of normal polarity for controlling westbound traffic movements. When relay K is energized and relay K is deenergized, relays Q will be energized by current of reverse polarity for controlling eastbound traffic movements.

When lever V is moved from its n to its k position, causing relays P and K to become deenergized and causing its contact 42 to close, relay Q will become energized in the normal direction, causing its contact 45 to remain closed in the position shown in the drawings. If switch J is in its normal position, if relay Q remains energized, and if track section GI-I is unoccupied, signal S will be operated to its proceed position. If, however, relay Q becomes deenergized, or if relay T is deenergized, signal S" will be operated to its proceed position.

Polarized relay Q controls, in part, a lock relay W which, in turn, controls lock magnet 11 for switch J Relay W is also controlled by a reverse polar contact of a polarized relay Y which is controlled by a back contact of an indication relay N and by pole-changing contacts operated by a lever V Lever V has a normal position m and a reverse position r. Relay W is also controlled by an approach relay t, by a manually operable push button h, and by a contact 1. Contact 7 is operated by the door of a case in which magnet 01 and lever X are enclosed. Contact 1 is normally open when this door is closed but becomes closed when the door is opened.

A switch indication relay U is controlled by a contact 62, which is operated by lever X, and by a contact 63 which is operated by switch J Contact 62 is closed when and only when lever X is in its normal position, and contact 63 is closed when and only when switch J is in its normal position.

Indication devices, here shown as electric lamps e and 6 are controlled by front and back points of contact 64 of relay N, respectively.

When lever V is moved to the right of its n position, causing relay K to be deenergized, and while relay K is energized, relay Q will be energized in the reverse direction, and hence relay R will be energized, causing signal S to be operated to the proceed position. If, after relay Q becomes energized in the reverse direction, the circuit for this relay should be broken, causing its neutral contact to open at its front point and to close at its back point, relay R will become energized for causing signal S to indicate proceed. When either relay R or R is energized and when lever V is at the same time in its r position while track relay T is energized and switch J is in its normal position, the arm of signal S will be moved to the proceed position.

Motor M is provided with a circuit by which it is caused to move switch J to its normal or its reverse position according as the polarity of the current supplied to this circuit is normal or reverse. Only a portion of this circuit, including wires l5 and I6 and contact ll of relay K is shown. It will be noted, therefore, that motor M can be operated for moving switch J only when relay K is energized.

Levers V V and V may be grouped together in some central location such, for example, as a train dispatchers ofiice.

In each of the drawings, the contacts operated by the various relays are identified by numbers, such numbers having exponents when the contacts are not shown adjacent the respective relays by which they are operated. The exponent for each of these contact numbers comprises the reference character and exponent for the respective relay. For example, the exponent T for contact 41' shown in the circuits for signals S and S comprises the reference character T and its exponent for track relay '1? which operates contact Having described, in general, the arrangement and control of the apparatus embodying invention, I will now trace in detail the operation of the various parts.

As shown in the drawings, all parts are in the normal condition, that is, levers V V and V are in their normal positions, signals S S S S and S are indicating stop. and stretch AI is unoccupied. With lever V in its 11 position, approach locking relay P is energized by a stick circuit passing from terminal x of a source of current not shown in the drawings, through contact 4 of lever V contacts 5, 6 and 1 of signals S S and S respectively, contact 8 of relay P and the winding of relay P to terminal 0 of the same source of current. With relay P energized and with track relay T energized, the pick-up circuit for relay K is closed. passing from terminal a, through con tact l2 of relay P contact [3 of relay T and the winding of relay K to terminal 0. The stick circuit for relay K is also closed, passing from terminal in, through contact I2 of relay P contact Id of relay K and the winding of relay K to terminal 0 With relay K energized, the portion of the circuit shown for motor M is closed through contact I? of relay K With lever V in its 12 position, relay P is energized by a stick circuit similar to that previously traced for relay P except passing through a contact 4* of lever V instead of through a contact 4 A pick-up circuit and a stick circuit for relay K similar to the pick-up and stick circuits traced for relay K are also closed.

With lever X in its normal position, and with switch J in its normal position, switch indication relay U is energized by a circuit passing from terminal :c, through contact 62 of lever X, contact 63 of switch J and the winding of relay U to terminal 0 Since track relays T and T are energized, approach relay t is energized by a circuit passing from terminal ac, through contact 48 of relay T contact 49 of relay T and the winding of relay t to terminal 0.

Indication relay N is deenergized, and hence indicator lamp e is lighted by a circuit passing from terminal as, through back point of contact 64 of relay N, and lamp e to terminal 0.

I will assume that with all parts thus in their tion G-H thereby permitting relay "I" to close its normal condition, the operator at the dispatchers office desires to clear =sigi-ial"S for a westbound train. He will therefore movelever V to its 7c position. This movement of lever V opens contact 4 causing relay P to become deenergized. The deenergization of relay P causes its contact I! to open, and hence relay K also becomes deenergized. With rel'ayK deenergized, a

circuit is completed for energizing relays Q in the normal direction, passing from terminal as, through back contact 23 of relay R back contact 24 of relay R front pointofcont'act 15 winding 'o f relay Q contact 26 of relay T winding of relay Q front point of contact 21* of relay T contact 28 of relay U, contact 290i relay T contact 30 of relay T windingofrelay Q back points of contacts-'31 and 32 of relay K wires 33 and 35,'and the frontpoint of contactilii to terminal 0. Relay Q thereupon closes its contact 46 at its front point and retains its polar contact 45 closed in the normal position shown in the drawings. With relay Q thus energized and with relay K deenergized, and with contact 42 of lever V closed because lever V has been moved to its is position, a circuit is completed for causing signal S to indicate proceed, passing from terminal at, through contact 42 of lever V contact 43 of switch J back contact 44 polar contact 45, front point of contact 4B of relay Q front point of contact 41'", and the mechanism of signals to terminal 0. I

If, before a train passes signal S, the operator decides to return' signal S to its stopposition in order to arrangefor some other traffic movement, he will return lever V to its n position. Contact 42 of lever V being thereby opened, the arm of signal S will return to its stopposition. With lever V in its n position, a circuit will now be completedfor relay L passing from terminal at, through contact 4 of lever V contacts 5, 6, and I of signals S 8 and 8 respectively, back point of contact 8 of relay P and the Winding of relay L to terminal 0. Upon the lapse of a given period of time, relay L will close its front contact ll, thereby. completing a pick-up circuit for relay P passing from' terminal a, through contact 4 of lever V contacts 5, 6 and? oi? signals S contact I l of relay L and the winding of relay P to terminal 0. Relay P upon becoming thus energized, completes its stick circuit previously traced through the front point of its contact 8, and opens,at the back point of its contact 8, the circuit for relay L causing relay L3 to become deenergized. With relay)? energized, the pick-up circuit for relay K is closed,

causing relay K to again become energized. With relay K energized, the operator can now arrange for the traffic movementde'sired.

I will now assume that all parts of the apparatus have again been returned to the normal condition, and that the operator has again cleared signal 5 for a westbound train. When such a train passes signal 5 it will deenergize relay 'I and so cause the arm of signal S to return to the stop position. If, now, the operator returns lever V to its n position, the circuit previously traced for relay 'L will be again completed. When the train passes out of section I-II, a second pick-up circuit will be completed for relay P passing from terminal :1:, through contact i of lever V contacts5, 6 and 1 of signals S back contact}! of relay '1", contact IQ of relay T and the winding of relay P to terminal 0. Relay K? can not, however, become energized until the train has passed out of seccontact I3 for completing the pick-up circuit for relay K As the train proceeds westward, relays T T T and T by becoming successively deenergized,

keep the circuit for relays Q open. It will thus be seen that from the time a train passes signal S until it leaves section CD, the circuit for relays Q is constantly open, making it impossible for relays Q to become energized in the reverse direction for permitting an eastbound train to enter the portion B H of the stretch of track shown in the drawings.

I will'next assume that the operator desires to "clear signals S and S for an eastbound train.

He will, therefore, move lever V to its 1' position. This causes contact 4 of lever V to break the stick circuit for relay P which thereupon becomes deenergizecl, causing relay K to also become deenergized. With relay K deenergized, a circuit is completed for energizing relays Q in the reverse direction, passing from terminal a, through the front point of "contact 3-1 of relay K winding of relay Q contact 30 of relay T contact '29 of relay'T contact 28 of relay U, contact "21 of relay T winding of relay Q contact 25 of relay T winding of relay Q back points of contacts 25 and 36 wires and '33, and from point of contact 32 of relay K to terminal 0; Relay Q being thus energizedin the reverse direction, clcses its polar contact 38 and closes its contact '39 at its front point, causing relay R to become energized by a circuit passing from terminal ac, through contact 31 polar contact 38, front point of contact 39 of relay Q and the winding of relay R to terminal 0. Relay R upon becoming thus energized, completes, at its contact 40. the circuit for signal S causing the 'arm of signal 8 to move to the proceed position. With lever V in its 1' position, the energization of relay R completes a circuit for causing signals to indicate proceed, passing from terminal as, through contact l8 of relay R contact 20 of switch J contact 2| of lever V contact 2'2", and the mechanism of signal S to terminal o.

From the time an eastbound train passes signals S until it leaves section B--C, relay K will remain deenergized, and while it is passing from signal S to signals S, the track relays T T T and T will become successively deenergized, causing the circuit for relays Q to be constantly deenergized. This makes it impossible for relays Q to become energized in the normal direction for permitting awestbound train movement while an eastbound train is moving from B to G.

After the first eastbound train passes signals S a second eastbound train will be given a callon indication by the arm of signal S This is accomplished through the deenergization of relay Q by thedeenergizat'ion of relay 'I With relay Q deenergized, relay R will be energized by a circuit passing from terminal :0, through contact 31 polar contact 38, back point of contact 39 of relay Q and the winding of relay R to terminal'o. The circuit for causing signal S to indicate proceed will'therefore be closed at back contact 65 of relay R 'and front contact 4| of relay R .If a westbound train is to use switch J in its reverse position, the operator will clear signal 5 as previously traced, and will then move lever V to itsr position. When the train arrives at switch J one of the trainm'en will open the door of the case which contains lock magnet d and lever X, thereby causing door contact 1 to close. The entrance of a train into section DE causes relay T to become deenergized, thereby completing a pick-up circuit for relay passing from terminal .E, through contact 50 of relay T and the winding of relay t to terminal 0. The operation of lever V to its 1" position by the operator has already caused relay Y to become energized in the reverse direction by a circuit passing from terminal 1:, through contact 5| of lever V in its reverse position, winding of relay Y, back contact 52 of relay N, and contact 53 of lever V in its reverse position to terminal 0. When the trainman causes door contact 1 to close, relays W and N will therefore become energized in series by a circuit passing from terminal :0, through contact 54 of relay Y, winding of relay N, contact 55 of relay 15, contact 55 of relay Q in its normal position, door contact J, winding of relay W, wire 35, and the front point of contact 36 toterminal 0.

Relay N, upon thus becoming energized, opens, at the back point of its contact 64, the lighting circuit for lamp e and closes, at the front point of contact 54, the lighting circuit for lamp e to indicate to the operator that the switch locking has been released so that the distant track switch can be reversed by the trainman.

With relay W thus energized, lock magnet d becomes energized by a circuit passing from terminal :L', through contact 59 of relay W, and the winding of magnet d to terminal 0. Magnet d, upon becoming energized, lifts its armature with dog Bil out of engagement with notch 6| of segment 9, thereby permitting movement of lever X, and at the same time operates a visual indicator comprising a miniature semaphore, as shown in the drawings to inform the trainman that the locking of lever X is released. The trainman will therefore move lever X to its 1' position, thereby withdrawing dog a from bar b. The trainman will then proceed to reverse switch J The movement of lever X to its 7 position has already opened the circuit for relay U, causing this relay to become deenergized. The deenergization of relay U causes a branch path to be completed for the control circuit for relay W, passing from the winding of relay N, through contact 58 to the winding of relay W. If the trainman should now close the door of the case for lever X permitting door contact 1 to again open while lever X is in its 1' position, relay W will continue energized by its circuit through contact 51W. Hence, if another switch besides switch J is also controlled by relay W, the lock magnet corresponding to magnet d, for the other switch would continue energized, thus permitting the trainman to operate the other switch if he should so desire as long as contact 58 is closed.

If an eastbound train is to set out a car over switch J reversed, the operator will move: lever V to its 1' position as already described, and will then move lever V to its 1' position. The circuit for relays Q being now energized in the reverse direction, contact 56 of relay Q is closed in its reverse position. When the train arrives on the detector section DE, and when the: trainman has caused contact 1 to close, relay W will remain released, as indicated by the condition of the visual indicator controlled by magnet d, and the trainman is thus informed that it will still be necessary for him to operate the normally open push button contact h before relay W will become energized. Since section D--E is occupied, track relay T is released, and operation of contact h completes a second branch path for the circuit for relays W and N, passing from the winding of relay N, through contact h, back contact 51, and contact 56 of relay Q in its reverse position to contact I. Magnet d being now energized, the trainman can operate lever X and switch J as already described.

If an engine is to move eastward to switch J and obtain a car and then return westward, the operator will first provide for the eastbound movement by operating lever V to its 1" position and, after the engine has passed signal 5 he will return lever V to its-n position, thereby conditioning a circuit for energizing relays Q and Q in the normal direction when the train moves out of section C-D, passing from terminal at, through contact 23 of relay R contact 24 of relay R front point of contact 25 winding of relay Q contact 26 of relay T winding of relay Q contact 21 of relay T a resistance unit 34, wire 35, and the front point of contact 36 to terminal 0. It will now be unnecessary for the trainman to operate push button h as previously described, since the circuit for relays W and N will now be closed through contact 56 of relay Q in its normal position.

From the foregoing description and the accompanying drawings, it follows that apparatus embodying my invention comprises a scheme of trafiic locking in which the directional control for signals is effected by approach locking relays for the two directions of trafiic. The signals for a given direction of trafiic are. controlled by a back contact of the approach locking relay for that direction and by a front contact of the approach locking relay for the opposite direction. Hence the entering signal, such, for example, as signal S, for a given direction can be cleared only when the approach locking relay P for the opposite direction is energized, thus insuring that signals S for the opposite direction are indicating stop. Furthermore, with this arrangement, the signals for a given direction of traffic movement can be cleared only when the approach locking relay for that direction is deenergized, thereby insuring that the signals for the opposite direction can not become cleared while the. signals for the first direction are indicating proceed.

Apparatus embodying my invention also comprises a scheme of circuits for an outlying look, by means of which the control, and normal and reverse indication for all switches controlled by the lock circuit require the use of only one wire in connection with the traffic locking control wires. With this arrangement, the approach locking relay for signals controlling traflic entering a given stretch against the current of trafiic serves as an approach locking relay for the outlying switch look as well.

Although I have herein shown and described only one form of railway traffic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a section of railway track including a switch, a second section of said track adjacent said first section, a signal for governing traffic movements over said switch, a track circuit for said first section including a track relay, a track circuit for said second section including a second track relay, a stick relay, a pick-up circuit for said stick relay including a back contact of said first track relay in series with a front contact of said second track relay, a stick circuit for said stick relay energizable when and only when said signal is controlled to indicate stop, a second stick relay, a pick-up circuit and a stick circuit for said second stick relay one of which is controlled by said first track relay and the other of which is controlled by said first stick relay, and means controlled by said second stick relay for controlling said switch.

2. In combination, a track circuit including a track relay, a second track circuit including a second track relay, a signal, a second signal, signal control means for controlling said first signal, a stick relay, a pick-up circuit and a stick circuit for said stick relay one of which includes a back contact of said first track relay in series with a front contact of said second track relay and the other of which is controlled by said signal control means, a second stick relay, a pick-up circuit and a stick circuit for said second stick relay one of which is controlled by said first track relay andthe other of which is controlled by said first stick relay, and means controlled by said second stick relay for controlling said second signal.

3. In combination, a track circuit including a track relay, a second track circuit including a second track relay, a signal, a control device, a stick relay, a pick-up circuit and a stick circuit for said stick relay one of which includes a back contact of said first track relay in series with a front contact of said second track relay and the other of which is controlled by said control device, a second stick relay, a pick-up circuit and a stick circuit for said second stick relay one of which is controlled by said first track relay and the other of which is controlled by said first stick relay, and means controlled by said second stick relay for controlling said signal.

4. In combination, a track circuit including a track relay,. a second track circuit including a second track relay, a signal, a control device, a stick relay, a pick-up circuit and a stick circuit for said stick, relay one of which is controlled by a back contact of said first track relay in series with a front contact of said second track relay and the other of which is controlled by said control device, a second stick relay, a pick-up circuit and a. stick circuit for said second stick relay one of which is controlled by said first track relay and the other of which is controlled by said first stick relay, and means controlled by said control device and by said second stick relay for controlling said signal.

5. In combination, a track circuit including a track relay, a second track circuit including a second track relay, a signal, a second signal, a control device, a stick relay, a pick-up circuit and a stick circuit forsaid stick relay one of which is controlled. by a back contact of said first track i relay in series with a front contact of said second track relay and the other of which is controlled by said control device, a second stick relay, a pickup circuit and a stick circuit for said second stick relay one of which is controlled by said first track relay and the other of which is controlled by said first stick relay, means controlled by a back contact of said second stick relay for controlling said first signal, and means controlled by a front contact of said second stick relay for controlling said second signal.

6. In combination, a stretch of railway track, a first plurality of traflic governing devices spaced along, said stretch for governing traffic movements in a first direction, a second plurality of traffic governing devices spaced along said stretch for governing trafiic movements in a second direction, an approach track circuit including a track relay adjacent one end of said stretch", a control device, a stick relay, a pick-up circuit and a stick circuit for said stick relay one of which is controlled by said approach track relay and the other of which is controlled by said control device, a second approach track circuit including a. second track relay adjacent the opposite end of said. stretch, a second control device, a. second stick relay, a pick-up circuit and a stick. circuit for said second stick relay one of which is controlled by said second approach track relay and the other of. which is controlled by said. second control device, means controlled by 'a front contact of said first stick relay and by a back contact of said second stick relay for controlling said first plurality of governing devices, and means controlled by a front contact of said second stick relay and by a back contact of said "first. stick relay for controlling said second plurality of governing. devices.

7.. Incombination, a stretch of railway track, a signaladjacent. one endof said stretch for governing traffic movements into said stretch in a given direction, a second signal adjacent the opposite end of said stretch for governing traffic movements into said stretch in the opposite direction, an approach trackv circuit including a track relay for said first, signal, a control device for controlling said first signal, a stick relay, a pick-up circuit and a stick circuit for said stick relay one of which is controlled by said approach track relay and the other of which is controlled by said control device, a second approach track circuit ineluding a second track relay for said second signal, a second control device for controlling said second signal, a second stick relay, a pick-up circuit and'a stick circuit for said second stick relayone of which is controlled by said second approach track relay and the other of which is controlled by said second control device, means controlled. by a back contact of said first stick relay anda front contact of said second stick relay for controlling said first signal, and means controlledby a back contact of said second stick relay and a front contact of said first stick relay for controlling said second signal.

8. In combination, a railway traffic governing device having a normal and a reverse position, a

vice, a control circuit for controlling said governing device including said indication device and said manually controllable contact in series, an indication contact which becomes closed when .55 manually controllable contact, an indication desaid governing, device is moved out of its normal position, and a branch path for said circuit inlocked in its normal position, a, signal for governing traffic over said switch and arranged to display a clear indication only when the indication relay is energized, a normally open manually operable contact adjacent said switch in the circuit for controlling said magnet, and a shunt for said contact comprising a back contact of said indication relay.

10. In combination, a railway track switch manually operable to a normal or to a reverse position, a normally restrained manually operable member for locking the switch in its normal position, a magnet for releasing said member, a control contact for said magnet located at a remote point and having a normal and a reverse position, a circuit for the control of said magnet including a line wire and the control contact in its reverse position, indication means associated with said contact for visually indicating when said circuit is closed, means effective when the circuit is closed for preventing said control contact being moved from its reverse to its normal position and means for opening the circuit to release the indicaticn means effective only when the track switch is locked in normal position.

11. In combination, a stretch of railway track, a signal adjacent one end of said stretch for governing traflic movements into said stretch in a given direction, a second signal adjacentthe opposite end of said stretch for governing traffic movements into said stretch in the opposite direction, a circuit serially connecting two route relays respectively associated with said signals and which circuit is energizable at both ends, two circuit controllers one associated with each end of said circuit each operable to efiect energization of said circuit but both normally ineffective, independent manually controlled devices located at a central oflice for respectively operating said circuit controllers for energizing said circuit from one end or the other, means for assuring that only one or said controllers can be eiiective at a time, an operating circuit controlled by each route relay when energized for clearing the associated signal, and means for causing only the operating circuit controlled by the route relay at the end at which the circuit controller is operated to be effective.

12. In combination, a stretch of railway track including a track switch, a signal adjacent one end of said stretch for governing trafiic movements into said stretch in a given direction, a second signal adjacent the opposite end of said stretch for governing trafiic movements into said stretch in the opposite direction, a circuit serially connecting two route relays respectively associated with said signals, and which circuit is energizable at both ends, two circuit controllers one associated with each end of said circuit each operable to effect energization of said circuit but both normally ineliective, independent manually controlled devices located at a central oflice for respectively operating said circuit controllers to energize the circuit at one end or the other, means for assuring that only one of said controllers can be effective at a time, other means for assuring that said circuit can be energized only when said switch is in a given position, and an operating circuit for each signal rendered effective to clear its signal only when the associated route relay is picked up and the associated circuit controller is in its operated position.

13. In combination, a stretch of railway track provided with a circuit serially connecting two route relays respectively associated with opposite directions or" traffic and which circuit is responsive to the condition of the traflic rails of the stretch, a current source associated with each direction of traffic for supplying current to said circuit but both normally ineilective, a signal normally indicating stop located at each end of the stretch to govern traffic in opposite directions through the stretch, a control circuit for each signal having two normally open contacts, means controlled by the energization of the route relay associated with the direction of trafiic which is governed by a signal for closing one of said open contacts of the control circuit of that signal, a first means controlled from a central ofiice for closing the second open contact of the control circuit of that signal, a second means controlled from the central office to render the current source associated with the direction of traffic governed by that signal effective to supply current to the route circuit, and means to prevent the central office means from rendering more than one current source effective at a, time.

14. In an interlocking system for railroads, a stretch of track divided into a plurality of track sections, two signals one at each end of said stretch oi track for governing traffic in opposite directions thereover, track switches associated with said track sections, means for operating said track switches, control levers for each of said signals, a directional stick relay for each track section containing a track switch, one of said stick relays being for one direction and the other of said stick relays being for the opposite direction, means locking at least one of said track switches when the directional stick relay for the corresponding track section is deenergized, and means clearing one of said signals only when the corresponding control lever is operated and the directional stick relay for the corresponding direction is deenergized.

15. In combination, a railway track switch, a lock relay which when deenergized prevents operation of the track switch, a manually operable switch control lever located at a point remote from the switch, a manually operable contact located adjacent the switch for rendering said lever effective to control the switch, a control circuit including said lock relay and having two branches each of which includes a contact closed when said lever is operated to control the switch one of said branches also including said manually operable contact, a track relay controlled by trafiic conditions adjacent the switch, and means controlled by said track relay for completing said control circuit under favorable track conditions when said lever is operated, even though said manually operable contact is not operated.

16. In combination, a railway track switch, a control lever at a point remote from the switch, a relay controlled by said lever and by traiiic conditions adjacent the switch, means eiTective if the relay is released to prevent operation of the switch, a manually operable contact adjacent the switch for at times picking up said relay, and an indicator adjacent said contact for visually indicating when said relay is released and said contact is to be operated.

17. In combination, a railway track switch, a control lever at a point remote from the switch, a relay controlled by traffic conditions adjacent the switch, a circuit for said relay governed by said control lever, means effective if the relay is released to prevent operation of the switch, a manually operable contact adjacent the switch for at times closing said circuit, indication means adjacent said contact controlled by said relay for indicating when said contact is to be operated,

' and indication means adjacent said control lever responsive to the flow of current in said circuit for indicating when said contact has been operated.

18. In combination, a railway track switch, a look relay which when deenergized prevents operation of the track switch, a circuit for said relay including in series a normally open manually operable contact adjacent the switch and a manually controlled contact at a point remote from the switch, and means normally effective under traffic conditions favorable for the operation of the switch for bridging said normally open manually operable contact.

19. In combination, a detector section of railway track including a track switch, a lock relay which when deenergized prevents operation of the track switch, a first normally open manually controlled contact at a point remote from the switch, a second normally open manually controlled contact adjacent the switch, a circuit for said lock relay including said two contacts in series, and means for completing said circuit to pick up said lock relay efiective if said contacts are simultaneously closed when said detector section is occupied.

EARL M. ALLEN. 

